The present invention relates to oral hygiene and specifically to the frequent cleansing of the oral cavity and interference with the formation of plaque. Plaque is a microbial coating on tooth surfaces, bound together by natural polymers, (mucopolysaccharides,) formed by microbial action on the cell debris, food remnants, sugars and starches in the mouth. Embedded in this polymer matrix are the bacteria normal to the oral cavity but, when trapped against tooth surfaces and protected by the matrix from easy removal, are in excellent position for "mischief." Most dental texts implicate plaque in the formation of caries, or tooth decay. In addition, these embedded bacteria release toxins that cause gingivitis, bleeding and swelling of the gums. Gingivitis can lead to periodontitis in which gums recede, pockets of infection form and teeth loosen.
Plaque formation is an ongoing process. Various gel and paste dentifrice preparations, mouth rinse and mouth prerinse preparations make plaque and/or tartar control claims. One disadvantage of these preparations is that only a relatively short time during which the teeth are being cleaned or the mouth is being rinsed is available for these preparations to take effect. These preparations generally have little residual effect on plaque formation. Additionally, some of these preparations such as mouth rinses and prerinses contain various antimicrobial substances which may alter the critically balanced microflora of the mouth. Another disadvantage of these preparations is the general infrequency of use. That is, most are used once or perhaps twice daily and seldom when they are most needed, e.g., after meals, snacks, smoking, drinking, coffeebreaks, etc.
Effective oral hygiene requires that three control elements be maintained by the individual:
1. Physical removal of stains, plaque and tartar. This is accomplished in the strongest sense by scraping and abrasion in the dentist's office. Self administered procedures are required frequently between visits and range from tooth brushing with an appropriate abrasive toothpaste through flossing and water jet action down to certain abrasive foods and even the action of the tongue against tooth surfaces.
2. Surfactant Cleansing. This is required to remove: food debris and staining substances before they adhere to the tooth surfaces; normal dead cellular (epithelial) material which is continually sloughed off from the surfaces of the oral cavity and microbial degradation products derived from all of the above. Besides the obvious hygenic and health benefits related to simple cleanliness provided by surfactants, there is an important cosmetic and sense-of-well-being benefit provided by surfactant cleansing. Research has shown that the primary source of bad breath is the retention and subsequent degradation of dead cellular material sloughed off continuously by the normal, healthy mouth.
3. Frequency of Cleansing. This is perhaps the most difficult to provide in today's fast-paced work and social environment. Most people recognize that their teeth should be brushed at least 3 times a day plus after each snacking occasion.
The simple fact is that most of the population brush once a day, some brush morning and evening, but precious few carry toothbrush and dentifrice to use the other three or four times a day for optimal oral hygiene. Consumer research suggests that the population brushes an average of 1.3 times a day. Thus, the 24 hour period between brushings for a majority of the population provides optimum plaque forming conditions with no interruptions.
Since plaque is regarded by most of the dental profession as a causitive agent leading to various dental pathologies as noted above, there is considerable desire by most consumers to remove or prevent the formation of plaque on a daily basis. There are three oral care strategies which address the problem of plaque: abrasion, anti-microbial agents and removal of precursors to plaque.
1. Abrasive removal of the plaque film, once it has firmly adhered to the tooth surface, is the only totally effective cleansing mechanism. Again, professional dental hygiene is the most effective, but recently a number of special abrasive toothpastes have been accepted by dental organizations as partially removing adhered plaque and the tartar which subsequently forms from the plaque.
2. Antimicrobial action could affect plaque formation in two ways, (a) reducing the number of bacteria in the mouth which form the mucopoly-saccharides and (b) killing those bacteria trapped in the film to prevent further growth and metabolism. However, the medical and dental community is divided about the advisability of frequent use of antimicrobial agents in the mouth in rinses or prerinses, especially the most effective ones, except under strict supervision of licensed practitioners. There are a number of reasons given, but one concern is that such materials would upset the ecological balance of the mouth. A balanced, "friendly" microbial population is necessary to prevent pathogenic organisms from taking over.
3. Removal of plaque precursors requires the reduction of food sources and building blocks required for the bacteria to synthesize the mucopolysaccharides which polymerize into the plaque film. Going far back into the chain of events leading to plaque formation and interrupting the chain has much to commend it as a sound oral hygiene strategy. However, for this strategy to be effective, the plaque building blocks must be interrupted periodically. As noted above, hereto, the oral hygiene preparations described about fall short on "frequency-of-use" basis.
For reference, see, L. Menaker, The Biologic Basis of Dental Caries, Chapters 5, 11, 12, 14 16 and 18, Harper & Row (1980).